Method and apparatus for powering-on a computer-based system via a network interface

ABSTRACT

A network interface card in a networked client computer includes a network interface circuit that decodes and then compares incoming network packet addresses to known address bit patterns, the decoding and comparing circuitry being powered at all time. Receipt and recognition of certain addresses means the client computer must be powered-on, even if manually switched OFF. When such a server-transmitted address is recognized, a power-on signal is issued to a power control unit that causes full operating power to be coupled to the client computer. In this fashion, a server can broadcast power-on signals to a plurality of networked client computers or workstations.

FIELD OF THE INVENTION

The present invention relates to networked computer-based systems, andmore specifically to powering-on such systems using network interfacesignals.

BACKGROUND OF THE INVENTION

A network is used to couple a host server computer to one or more clientcomputers, using wires (including telephone wires), fiber optics, orwireless signals. There are at least several million computers in theUnited States alone, and an increasing number of these computers arebecoming network-accessible.

FIG. 1 depicts a generic network 10 that includes a server 20 and one ormore client computers or workstations 30, 30' that each include acentral processing unit ("CPU") 40, 40'. (As used herein, the termcomputer shall be understood to include the term workstation.) Theserver and clients communicate over information paths 50, 50' that, asnoted, may be wires, optical cables, or radio transmissions. Paths 50,50'may be parallel, e.g., a plurality of wires, or may be serial, e.g.,a single data line. At the client end, each computer includes a networkinterface circuit 60, 60'.

Network interface controller 60, 60' typically is an integrated circuit("IC") chip that provides interfacing between the client computer andthe remote host/server. According to current Ethernet network protocol,networked computers rely upon three attributes of the network: (a) thenetwork is always up or active, (b) the client computer is always aliveand coupled to the network, and (c) data and/or application programs maybe run locally or run remotely over the network from another computer.

Each computer 30, 30' includes a power supply that is typically coupledto 110 VAC/220 VAC, and whose output DC voltages are coupled through anON/OFF power switch relay, here depicted as a manually operated switchSi, or S1'. If the computer is to communicate with the network, thepower switch is ON, otherwise there is no operating voltage to thecomputer. Although Si is depicted as a manually operated switch, it isunderstood that power may be switched on or off using other switchingdevices, including electronic switching devices.

A single desktop computer such as computer 30 or 30' may only consumeperhaps 150 watts of electrical power. However, cumulatively theelectrical power consumed by all of the computers in the United States,and indeed in the world, is becoming appreciable. With a view toreducing this power consumption and the environmental cost involved ingenerating the power, the United States Federal Government haspromulgated the Energy Star program.

As applicable to the present invention, the Energy Star program requiresthat computers be powered-off to a low energy state of less than 30watts consumption during periods of inactivity. Computers meeting thisrequirement, so-called "green PCs", are permitted to bear an Energy Starinsignia. Conversely, non-Energy Star compliant equipment is often lesswell received in the commercial marketplace.

One approach to complying with the Energy Star requirement is to designlower power consumption equipment, laptop computers, for example. Manycomputers can also benefit from advanced power management features,including features that are incorporated into the computer operatingsystem. Intel Corp. and Microsoft Corp. collectively have promulgatedone such Advanced Power Management specification.

Using power management, a computer can power-down its harddisk and slowits CPU clock rate, thus saving electrical power, after inactivityexceeding a certain threshold. Depressing a key on the computerkeyboard, or moving a mouse or other control device will "awaken" thecomputer, restoring it to full CPU clock rate and/or reactivating thehard disk, within a few seconds.

However, powering-off a networked Energy Star compliant computer duringperiods of inactivity detrimentally interrupts established events thatconstantly occur in a networked computing environment, polling forexample. In practice, powering-off a networked computer could readilymake such a computer a pariah in the network marketplace. It is thusdesirable to maintain some operating power, preferably less than 30watts, to a networked computer to permit the computer to respond to thenetwork without being manually awakened.

It is known in the art to remotely awaken a powered-off computer with afacsimile ("FAX") signal or a modem signal coupled to the computer'sserial port from the telephone line. However such "awakening" requires aFAX or modem signal to be sent to the specific telephone numberassociated with the computer's modem. The modem must be powered at alltimes and may consume from 5 watts to 10 watts power.

Thus, there is a need to make a networked computer Energy Starcomplaint, without risk of interrupting network functions that can occureven during periods of client-system inactivity. Preferably the computershould be capable of being powered-off, and then "awakened" using onlysignals available from the network and coupled to the network interfacecard. Further, there is a need for a mechanism or system by which alarge number of networked computers can be powered-on, quickly or evensimultaneously.

The present invention discloses a method and apparatus for accomplishingthese needs.

SUMMARY OF THE INVENTION

A network interface card in a networked client computer includes asoftware or hardware mechanism that is powered at all times. Thismechanism decodes incoming network packets and recognizes therein aserver-transmitted address whose receipt means the client must bepowered-on, even if it had been manually switched off. The transmittedaddress may be a "broadcast" address whose receipt will cause power-onof all recipient client computers on the network. This address mayinstead be a client-dedicated address whose receipt will cause power-ononly in client computers whose decode and recognition mechanismrecognizes this address.

Within the network interface card, the address comparison may beimplemented in hardware using register comparator logic, or in softwareusing a hashing algorithm. In either event, the decoding and addressrecognizing mechanism operates with less than 30 watts power and ispowered at all times.

Upon receipt, decoding and recognition of a broadcast or client address,the decode and recognition mechanism outputs a signal that activates apower control circuit within the network interface card. The powercontrol circuit is coupled between the DC power source and the client,and activation closes this circuit, bringing full operating DC voltageand thus full power-on to the client.

Full power-on condition will occur within a few seconds, regardless ofwhether the client computer was in a power-off mode or was switched offmanually. The present invention permits a server to broadcast a power-onaddress whose receipt will cause each of a plurality of clients coupledto the network to power-on simultaneously.

Other features and advantages of the invention will appear from thefollowing description in which the preferred embodiments have been setforth in detail, in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a generic network, according to the prior art;

FIG. 2 is a block diagram of a portion of a network interface card andpower control circuitry, according to the present invention;

FIG. 3 is a flow diagram depicting steps in recognizing a networkbroadcast power-on indicating address, and in powering-on a networkedclient computer, according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 2 depicts a client computer (or workstation) 30 that includes a CPU40, and a modified network interface card 200 according to the presentinvention. Computer 30 is coupled, via line or lines 50 to a networkserver 20, such as server 20 in FIG. 1.

Among line(s) 50 are line(s) 90 that can carry packets of informationbroadcast by server 20 to all client computer 30, 30', etc. coupled tothe network. Although FIG. 2 depicts path 50 as including a plurality oflines including lines 90, e.g., parallel coupling, a single serial line(e.g., a single line 50 or line 90) configuration could instead be used,depending upon the network electrical specification.

The information broadcast by server 20 over line(s) 50 is in packetformat, with each packet comprising a number of bytes. Packet size maybe 48 bytes in certain protocols, each packet including an address fieldof 6 bytes, or 48 bits. In some protocols, the first 24 bits of anaddress field are organization address blocks, which contain bitpatterns unique to the organization producing the hardware. Someorganization address blocks are defined on an industry-wide basis. Forexample, within the IEEE Ethernet protocol, a string of 24 0 's denotesa null packet, which recipient clients may ignore.

As described below, the present invention utilizes client receipt andrecognition of certain server-transmitted address patterns to commandpower-on within a recipient networked client, even if the client hadbeen manually turned-off.

Referring to FIG. 2, DC operating power to computer 30 is provided by aninternal power supply (not shown) on line 70 that is coupled by a switchmechanism, here shown as a switch S1, into the computer at node 80. Ifswitch S1 is in the OFF position, operating power to computer 30 isinterrupted. However, a small amount of operating power is still coupledto at least a portion of a network interface circuit 100 via a powerlead 110, and is also provided as an input to a power control circuit130. Alternatively, a split power plane or a battery could be used topower the network interface circuit 100. Circuit 100 is powered at alltimes and will consume less than the 30 watts mandated by the EnergyStar program. Actual circuit 100 power consumption depends upon thenature of the server-to-client coupling but will typically range from 5watts to 10 watts.

If switch S1 is in the ON position, computer 30 receives full operatingpower, with CPU 40 being coupled via lead 85 to powered node 80.However, computer 30 may enter energy saving modes in which the computerhard disk (not shown) ceases rotation, and in which CPU 40 is clocked ata relatively slower rate, or completely halted.

It is to be understood that full operating power need not pass throughswitch Si, and that node 80 may in fact be the input node of a latchdevice within computer 30. Upon receipt of a DC signal at node 80, suchlatch device can switch the full operating power on to power computer30.

Network interface circuit 100 is coupled by line (or lines) 90 to server20, and to client CPU 40 by the local CPU data bus 45. Operating poweris always available to circuit 100 via a power lead 110 that comes fromthe power source side of switch S1.

Circuit 100 includes an address decoder 102 and a comparator 104 thatcompares the decoding incoming address received via line(s) 90 against astored bit pattern representing an address whose receipt means computer30 should enter power-on. The comparator could, for example, includelogic allowing a user of computer 30 to program not only the addressesto be recognized, but also to determine whether power-on should occureven if recognition is made. At a minimum, the portion of circuit 100including decoder 102 and comparator 104 receive operating power at alltimes, but the rest of circuit 100 need not be powered at all times. Ofcourse several such address bit patterns may be stored, including forexample, a broadcast address pattern and a client address pattern.

Comparator 104 may be implemented in hardware using conventionalhardware registers and comparator logic. Alternatively, comparator 104may be implemented in software to shorten comparison time and reducecost of implementation and/or power consumption. In a softwareimplementation, comparator 104 includes a hash table and will firstcompare most significant bit portions of an incoming packet address. Ahashing algorithm is executed within the interface controller unit. Ifmatched, less significant bit portions are compared until a completebroadcast or client address match is recognized.

However implemented, if unit 100 recognizes an address match, a"power-on" signal is coupled over lead 120 to the input of a powercontrol unit 130 that is coupled in parallel across switch S1. Powercontrol circuit 130 may be a single power control integrated circuit("IC"), a MOSFET switch, or other latch-accomplishing mechanism.

Upon receipt of this signal, power control unit 130 "closes", couplingtogether power-carrying line 110 and line 70 with line 140. CPU 40 nowreceives operating voltage via lead 85, and computer 30 can enter a fullpower-up state within one or two seconds, even if S1 is open.

Thus, when server 20 broadcasts a address over line(s) 90 whose receiptand recognition by circuit 100 commands a power-on of computer 30, unit100 triggers power control unit 130, which provides full operating powerto computer 30. Power-on occurs regardless of whether computer 30 is inan Energy Star low-power mode (e.g., where S1 was in the ON position topower-on computer 30, but has been turned OFF as a result of Energy Starmechanisms), or is in a power-off mode (e.g., with S1 in the OFFposition). In the low-power mode, although S1 will have been in the ONposition, CPU 40, hard disk(s) (not shown) and other power consumingcomponents within computer 30 will have entered power saving modes,e.g., operating and using less than 30 watts.

In the above fashion, one or a plurality of client computers 30 may besimultaneously forced to enter a power-on state using addressinformation broadcast by a network server. This is in contrast to theprior art use of a telephone line and modem to dial a dedicatedtelephone number for a given computer to remotely command the computerto power-on.

FIG. 3 depicts the various method steps used to carry out the presentinvention. Initially, at method step 300, it is assumed that S1 is OFF,and that no DC operating potential is coupled to node 80 of computer 30.

At step 310, if switch S1 is ON (or activated), then at step 350 DCpower is coupled to CPU 40 and indeed to computer 30. If, however, CPU40 is inactive for 30 minutes as determined by step 360, Energy Starcompliance mandates that, at step 300, CPU power be interrupted, e.g.,S1 returned to OFF.

Returning to step 310, even if Si is OFF, unit 100 receives operatingpower and examines incoming address information communicated overline(s) 90.

Within unit 100, if a comparison match is found between the incomingaddress and a bit pattern known to represent a broadcast addresscommanding a power-on condition, step 330 returns to step 350 and theCPU power is turned ON by activating power control unit 130 via line120. However, as noted, user-programmable logic may be provided tooverride turn-on, even if a broadcast match occurs. As before, at step360, after 30 minutes of inactivity, the Star Energy-compliant clientwill interrupt CPU power at step 300 by causing S1 to be OFF, and bypower control unit 130 to open circuit.

However, if step 330 does not result in a broadcast address match, atstep 340 a determination is made by unit 100 to determine whether theincoming address represents an address commanding a power-on conditionof this particular computer 30.

If an address match occurs, then at step 350 power control unit isactivated, providing operating DC voltage to computer 30. However, asnoted, user-programmable logic may be provided to override power-on,even if a client address match occurs. Such logic could, if desired,flexibly permit a broadcast address match but not a client address matchto cause power-on, or the converse.

If, however,step 340 does not recognize the incoming address, theroutine returns to step 300 and computer 30 remains off.

Modifications and variations may be made to the disclosed embodimentswithout departing from the subject and spirit of the invention asdefined by the following claims.

What is claimed is:
 1. In a peer-to-peer network including a server thatbroadcasts information packets to each client coupled to said networkincluding any clients whose operating voltage is switched off, a methodfor powering-on the switched-off clients, the method including thefollowing steps:providing each client coupled to said network with anetwork interface coupled to receive said information packets, at leasta portion of said network interface receiving operating voltage at alltimes and including a decoder, a comparator that includes a hashingalgorithm executed within said network interface, and a power controlunit; said decoder decoding address information included in saidinformation packets; said comparator comparing decoded said addressinformation with at least one stored pattern of bits representing apower-on condition, said comparator outputting a power-on signal to saidpower control unit when a said stored pattern of bits matches thedecoded said address information; said power control unit coupled toprovide operating voltage to each powered-off client upon receipt ofsaid power-on signal; wherein at least one said client is Energy Starcompliant.
 2. The method of claim 1, wherein said network interfacestores at least a first pattern of bits representing a broadcastaddress, and a second pattern of bits representing a clientaddress;wherein said comparator outputs said power-on signal when thedecoded said address information matches either of said first pattern ofbits or said second pattern of bits.
 3. The method of claim 1, whereincollectively said decoder and said comparator consume less than 30 wattsof operating power.
 4. The method of claim 1, wherein said networkfurther includes a second client, receiving said information broadcastby said server, whose operating voltage is switched-off, said methodpowering-on each said client coupled to said network;said second clientincluding a second network interface coupled to receive said informationpackets, said second network interface at least of portion of whichreceives operating voltage at all times and including a second decoder,a second comparator, and a second power control unit; said seconddecoder decoding address information included in said informationpackets; said second comparator comparing decoded said addressinformation with at least one stored pattern of bits representing apower-on condition, said second comparator outputting a power-on signalto said second power control unit when a said stored pattern of bitsmatches the decoded said address information; said second power controlunit coupled to provide operating voltage to said second client uponreceipt of said power-on signal; wherein each powered-off client ispowered-on simultaneously when said decoded said address informationmatches said stored pattern of bits.
 5. The method of claim 1, whereinsaid comparator includes register comparator logic hardware.
 6. Themethod of claim 1, wherein said power control unit is selected from thegroup consisting of a power control integrated circuit, and a MOSFETswitch.
 7. In a peer-to-peer network including a server that broadcastsinformation packets to each client coupled to said network including atleast a first client whose operating voltage is switched-off, and asecond client whose operating voltage is switched off;said first clientincluding a first network interface having a first decoder that decodesaddress information included in said information packets, and saidsecond client including a second network interface having a seconddecoder that decodes decoder address information included in saidinformation packets, a method for powering-on said first client and saidclient, the method including the following steps:providing operatingvoltage at all times to at least a portion of said first networkinterface and to at least a portion of said second network interface;providing said first network interface with a first comparator thatincludes a hashing algorithm executed within said first networkinterface, and a first power control unit; providing said second networkinterface with a second comparator, and a second power control unit;said first comparator comparing decoded said address information with atleast one stored pattern of bits representing a power-on condition, andoutputting a power-on signal to said first power control unit when asaid stored pattern of bits matches the decoded said addressinformation; said second comparator comparing decoded said addressinformation with at least one stored pattern of bits representing apower-on condition, and outputting a power-on signal to said secondpower control unit when a said stored pattern of bits matches thedecoded said address information; said first power control unit coupledto provide operating voltage to said first client upon receipt of saidpower-on signal from said first comparator, and said second powercontrol unit coupled to provide operating voltage to said second clientupon receipt of said power-on signal from said second comparatorswherein at least one said client is Energy Star compliant.
 8. The methodof claim 7, wherein said first network interface and said networkinterface each store at least a first pattern of bits representing abroadcast address, and a second pattern of bits representing a clientaddress;wherein each said comparator outputs a power-on signal when thedecoded said address information matches either of said first pattern ofbits or said second pattern of bits.
 9. The method of claim 7, whereincollectively said first decoder and said first comparator consume lessthan 30 watts of operating power.
 10. The method of claim 7, whereinsaid first comparator includes register comparator logic hardware. 11.The method of claim 7, wherein said first power control unit is selectedfrom the group consisting of a power control integrated circuit, and aMOSFET switch.
 12. In a peer-to-peer network including a server thatbroadcasts information packets to each client coupled to said networkincluding at least one client whose operating voltage is switched off, asystem for powering-on the switched off client, the system comprising:anetwork interface, for each client coupled to said network, coupled toreceive said information packets, said network interface including adecoder, a comparator including a hashing algorithm executed within saidnetwork interface, and a power control unit, said decoder, comparatorand power control unit each receiving operating voltage at all times;said decoder decoding address information included in said informationpackets; said comparator comparing decoded said address information withat least one stored pattern of bits representing a power-on condition,said comparator outputting a power-on signal to said power control unitwhen a said stored pattern of bits matches the decoded said addressinformation; said power control unit coupled to provide operatingvoltage to said powered-off client upon receipt of said power-onsignal;wherein at least one said client is Energy Star compliant. 13.The system of claim 12, wherein said network interface stores at least afirst pattern of bits representing a broadcast address, and a secondpattern of bits representing a client address;wherein said comparatoroutputs said power-on signal when the decoded said address informationmatches either of said first pattern of bits or said second pattern ofbits.
 14. The system of claim 12, wherein collectively said decoder andsaid comparator consume less than 30 watts of operating power.
 15. Thesystem of claim 12, wherein said peer-to-peer network further includes asecond client, receiving said information broadcast by said server,whose operating voltage is switched off, and wherein said systempowers-on each said client;said second client including a second networkinterface coupled to receive said information packets, said secondnetwork interface receiving operating voltage at all times and includinga second decoder, a second comparator, and a second power control unit;said second decoder decoding address information included in saidinformation packets; said second comparator comparing decoded saidaddress information with at least one stored pattern of bitsrepresenting a power-on condition, said second comparator outputting apower-on signal to said second power control unit when a said storedpattern of bits matches the decoded said address information; saidsecond power control unit coupled to provide operating voltage to saidsecond client upon receipt of said power-on signal; wherein eachPowered-off client is powered-on simultaneously when said decoded saidaddress information matches said stored pattern of bits.
 16. The systemof claim 12, wherein said comparator includes register comparator logichardware.
 17. The system of claim 12, wherein said power control unit isselected from the group consisting of a power control integratedcircuit, and a MOSFET switch.